X-ray

Distribution by Scientific Domains

Kinds of X-ray

  • abdominal x-ray
  • chest x-ray
  • coherent x-ray
  • combined x-ray
  • dispersive x-ray
  • energy dispersive x-ray
  • hard x-ray
  • high-energy x-ray
  • incident x-ray
  • plain abdominal x-ray
  • plain x-ray
  • small-angle x-ray
  • soft x-ray
  • softer x-ray
  • synchrotron x-ray

  • Terms modified by X-ray

  • x-ray absorptiometry
  • x-ray absorption
  • x-ray absorption fine structure
  • x-ray absorption fine structure spectroscopy
  • x-ray absorption near-edge structure
  • x-ray absorption spectroscopy
  • x-ray absorption spectrum
  • x-ray analysis
  • x-ray analysis.
  • x-ray background
  • x-ray band
  • x-ray beam
  • x-ray beamline
  • x-ray binary
  • x-ray characterization
  • x-ray component
  • x-ray counterpart
  • x-ray crystal structure
  • x-ray crystal structure analysis
  • x-ray crystal structure analysis.
  • x-ray crystal structure determination
  • x-ray crystallographic analysis
  • x-ray crystallographic data
  • x-ray crystallographic investigation
  • x-ray crystallographic structure
  • x-ray crystallographic studies
  • x-ray crystallographic study
  • x-ray crystallography
  • x-ray crystallography analysis
  • x-ray data
  • x-ray data collection
  • x-ray data set
  • x-ray detection
  • x-ray detector
  • x-ray diffraction
  • x-ray diffraction analysis
  • x-ray diffraction analysis shows
  • x-ray diffraction analysis.
  • x-ray diffraction data
  • x-ray diffraction data collection
  • x-ray diffraction data set
  • x-ray diffraction experiment
  • x-ray diffraction investigation
  • x-ray diffraction measurement
  • x-ray diffraction method
  • x-ray diffraction methods
  • x-ray diffraction pattern
  • x-ray diffraction profile
  • x-ray diffraction result
  • x-ray diffraction shows
  • x-ray diffraction spectrum
  • x-ray diffraction structure
  • x-ray diffraction studies
  • x-ray diffraction studies.
  • x-ray diffraction study
  • x-ray diffraction technique
  • x-ray diffraction techniques
  • x-ray diffractometer
  • x-ray diffractometry
  • x-ray dose
  • x-ray emission
  • x-ray emission spectroscopy
  • x-ray energy
  • x-ray examination
  • x-ray excitation
  • x-ray exposure
  • x-ray film
  • x-ray flare
  • x-ray fluorescence
  • x-ray fluorescence analysis
  • x-ray fluorescence spectrometry
  • x-ray fluorescence spectroscopy
  • x-ray fluoroscopy
  • x-ray flux
  • x-ray free-electron laser
  • x-ray generator
  • x-ray illumination
  • x-ray image
  • x-ray imaging
  • x-ray intensity
  • x-ray intensity data
  • x-ray investigation
  • x-ray irradiation
  • x-ray light curve
  • x-ray luminosity
  • x-ray luminosity function
  • x-ray magnetic circular dichroism
  • x-ray mapping
  • x-ray measurement
  • x-ray methods
  • x-ray microanalysi
  • x-ray microscope
  • x-ray microscopy
  • x-ray observation
  • x-ray observatory
  • x-ray optics
  • x-ray photoelectron spectroscopy
  • x-ray photoelectron spectroscopy analysis
  • x-ray photoelectron spectrum
  • x-ray photoemission spectroscopy
  • x-ray photon correlation spectroscopy
  • x-ray powder diffraction
  • x-ray powder diffraction data
  • x-ray powder diffraction pattern
  • x-ray powder diffraction studies
  • x-ray powder diffractometry
  • x-ray powder pattern
  • x-ray property
  • x-ray pulse
  • x-ray radiation
  • x-ray reflection
  • x-ray reflectivity
  • x-ray reflectivity measurement
  • x-ray region
  • x-ray rocking curve
  • x-ray scattering
  • x-ray scattering data
  • x-ray scattering experiment
  • x-ray scattering investigation
  • x-ray scattering measurement
  • x-ray scattering studies
  • x-ray scattering techniques
  • x-ray single crystal analysis
  • x-ray single crystal diffraction
  • x-ray single-crystal analysis
  • x-ray single-crystal diffraction
  • x-ray source
  • x-ray spectrometer
  • x-ray spectrometry
  • x-ray spectroscopy
  • x-ray spectrum
  • x-ray structural analysis
  • x-ray structural studies
  • x-ray structure
  • x-ray structure analysis
  • x-ray structure determination
  • x-ray studies
  • x-ray study
  • x-ray survey
  • x-ray techniques
  • x-ray telescope
  • x-ray tomography
  • x-ray topography
  • x-ray transient
  • x-ray variability
  • x-ray wavelength

  • Selected Abstracts


    5-Benzyl-3-methylimidazolidin-4-one-Derived Reactive Intermediates of Organocatalysis , A Comforting Resemblance of X-Ray, NMR, and DFT Solid-Phase, Liquid-Phase, and Gas-Phase Structures

    HELVETICA CHIMICA ACTA, Issue 1 2009

    Abstract The X-ray crystal structures of three (E)-1-cinnamoylidene iminium PF6 salts of 5-benzyl-3-methylimidazolidin-4-ones (2,2-dimethyl-, cis -2-(tert -butyl)-, and cis -2-styryl-substituted; 2,4, resp.) are reported (Figs.,3,5). In the 2,2-dimethyl and in the cis -2-styryl derivative, 2 and 4, respectively, a CH bond of the cis -substituent in 2-position points to the center of the benzene ring of the benzyl group above the five-membered ring (Fig.,6,,a and b). NMR Measurements (Fig.,8) provide evidence that the same structure is present in solution, and that a fourth derivative of this type, 5 (Scheme), has (Z)- instead of (E)-configuration around the CN bond. In the cis -2-(tert -butyl) derivative 3, the benzyl group is located over the iminium , -system (Figs.,4 and 6,,c). Overlays with DFT-calculated crotonylidene analogs, A and B, show that the theoretical and experimental structures are almost superimposable (Fig.,9 and Table). The structures are discussed in view of their role as reactive intermediates in organocatalysis and in view of the help synthetic organic chemists may experience from theory. [source]


    Chronic lymphocytic leukemia presenting as cutaneous and bone involvement

    INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 1 2001
    Maria P. Stefanidou MD
    An 84-year-old man had a 3-year history of a progressive, painless, papulonodular eruption, that was particularly prominent on the face and extremities. Physical examination revealed firm, bluish-red nodules and plaques, located on the tip of the nose, the cheeks, ears, and distal digits. Skin lesions produced a leonine facies (Fig. 1), deformities of the fingers and toes, finger clubbing, and onyxis. An identical lesion was seen on a postoperational scar on the left cheek. The mucous membranes were spared. The patient had anterior and posterior cervical and bilateral axillary lymphadenopathy and splenomegaly. Figure 1. Leonine facies On admission, the peripheral blood count revealed 260,000/mm3 leukocytes (lymphocytes 97%, neutrophils 2%, and monocytes 1%), a hemoglobin level of 9.5 g/dL, and platelet count of 100,000/mm3. Hypogammaglobulinemia with reduction of immunoglobulin G (IgG) and IgM was found. Radiography of the fingers showed multiple osteolytic lesions of the phalanges and phalangette destruction of the left median finger (Fig. 2a,b). Computed tomography of the chest and abdomen revealed bilateral axillary, mediastinal, and para-aortic lymphadenopathy and spleen enlargement. Figure 2. X-Ray of the hands: (a) ,multiple osteolytic lesions of the phalanges and (b) ,partial destruction of the left median phalangette Skin biopsy specimens from the ear and finger lesions showed a massive nonepidermal leukemic infiltration in the papillary and reticular dermis, with a grenz zone consisting of small lymphocytes (Fig. 3). Figure 3. Skin biopsy (hematoxylin and eosin, ×,250). Massive leukemic infiltration consisting of small lymphocytes. Subepidermally, a grenz zone of connective tissue is noted Biopsy of the enlarged cervical lymph node showed a diffuse infiltration with lymphocytes. Tissue biopsy from a finger lytic lesion revealed infiltration of bone trabecular and fibrous tissue with a dense population of small- and medium-sized lymphocytes. Immunohistochemical study of cutaneous and bone lesions showed that the infiltrate in both biopsies consisted mainly of B lymphocytes (CD20+, CD45R+, CD45Ro,, OPD4,). Peripheral blood smear had a B-cell phenotype (CD19 98%, CD20 97%, CD23 99%, CD25 40%, CD5 90%, HLA-DR 100%). Bone marrow smear and immunophenotyping surface marker analysis found a diffuse pattern of B-lymphocytic infiltration. A diagnosis of B-cell chronic lymphocytic leukemia stage C (Binet staging system), with specific cutaneous and bone lesions, was established. The patient received chemotherapy with chlorambucil and methylprednisolone, which resulted in improvement of the hematologic profile. Two years later, the cutaneous lesions showed partial remission. [source]


    Unexpected cardiovascular collapse from massive air embolism during endoscopic retrograde cholangiopancreatography

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 3 2010
    K. M. GOINS
    A 72 year-old woman with cholangiocarcinoma presented for endoscopic retrograde cholangio pancreatography (ERCP) for diagnostic intraductal endoscopy under GETA. During the technically difficult procedure the patient became suddenly hypoxic, hypotensive, bradycardic, and progressed to PEA code (ETCO2 5 mmHg). ACLS was initiated. Transesophageal echo demonstrated massive right heart air accumulation; abdominal X-Ray showed air filled bile ducts. Central access was obtained, a pulmonary artery catheter floated, and 30 ml of air aspirated from the RV. Within 5 minutes pulses returned; the patient was transferred to the ICU. MRI revealed two watershed infarcts in the right frontal lobe. The patient fully recovered and returned a month later for an uneventful ERCP. [source]


    A Novel Approach to Study Biscuits and Breadsticks Using X-Ray Computed Tomography

    JOURNAL OF FOOD SCIENCE, Issue 6 2010
    P. Frisullo
    Abstract:, In this study X-ray microtomography (,CT) was used for analysis of the microstructure of 6 different types of Italian biscuits and 3 types of Italian breadsticks. Appropriate quantitative 3-D parameters describing the microstructure were calculated, such as the structure thickness (ST), the object structure volume ratio (OSVR), the degree of anisotropy (DA), and the percentage object volume (POV). Sensory analysis was also performed to discriminate samples on the basis of texture characteristics. A correlation between microstructural data (OSVR for biscuits and OSVR, POV, and DA for breadsticks) and sample crunchiness was also found. Results obtained from the current study showed that analysis at a microscopic level could be useful to the food industry, as the accurate calculation of number, dimension, and distribution of pores in the products could be used to improve the sensorial properties of food. Further study by ,CT could be carried out to correlate microstructure to specific ingredients and process conditions to allow obtaining more tailored food. [source]


    ChemInform Abstract: Structural Investigation of Tetraperoxo Complexes of Mo(VI) and W(VI) , X-Ray and Theoretical Studies.

    CHEMINFORM, Issue 28 2009
    M. Grzywa
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    Crystalline, Mixed-Valence Manganese Analogue of Prussian Blue: Magnetic, Spectroscopic, X-Ray and Neutron Diffraction Studies.

    CHEMINFORM, Issue 13 2005
    Silvio Decurtins
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]


    X-Ray and Neutron Diffraction Studies on "Li4.4Sn".

    CHEMINFORM, Issue 37 2003
    Corina Lupu
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]


    Theoretical Analysis of the Triplet Excited State of the [Pt2(H2P2O5)4] 4- Ion and Comparison with Time-Resolved X-Ray and Spectroscopic Results

    CHEMINFORM, Issue 18 2003
    Irina V. Novozhilova
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]


    ChemInform Abstract: Crystal Structure of Superconducting K3Ba3C60: A Combined Synchrotron X-Ray and Neutron Diffraction Study.

    CHEMINFORM, Issue 1 2001
    Serena Margadonna
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    Cyclic ,-Tetra- and Pentapeptides: Synthesis through On-Resin Cyclization and Conformational Studies by X-Ray, NMR and CD Spectroscopy and Theoretical Calculations

    CHEMISTRY - A EUROPEAN JOURNAL, Issue 21 2005
    Frank Büttner Dr.
    Abstract The solution-phase synthesis of the simplest cyclic ,-tetrapeptide, cyclo(,-Ala)4 (4), as well as the solid-phase syntheses through side chain anchoring and on-resin cyclization of the cyclic ,3 -tetrapeptide cyclo(-,3hPhe-,3hLeu-,3hLys-,3hGln-) (14) and the first cyclic ,3 -pentapeptide cyclo(-,3hVal-,3hPhe-,3hLeu-,3hLys-,3hLys-) (19) are reported. Extensive computational as well as spectroscopic studies, including X-ray and NMR spectroscopy, were undertaken to determine the preferred conformations of these unnatural oligomers in solution and in the solid state. cyclo(,-Ala)4 (4) with no chiral side chains is shown to exist as a mixture of rapidly interchanging conformers in solution, whereas inclusion of chiral side chains in the cyclo-,3 -tetrapeptide causes stabilization of one dominating conformer. The cyclic ,3 -pentapeptide on the other hand shows larger conformational freedom. The X-ray structure of achiral cyclo(,-Ala)4 (4) displays a Ci -symmetrical 16-membered ring with adjacent CO and N-H atoms pointing pair wise up and down with respect to the ring plane. CD spectroscopic examinations of all cyclic ,-peptides were undertaken and revealed results valuable as starting point for further structural investigations of these entities. [source]


    Preparation and characterization of electrodeposited indium selenide thin films

    CRYSTAL RESEARCH AND TECHNOLOGY, Issue 6 2005
    S. Gopal
    Abstract Indium Selenide (InSe) thin films were deposited from a mixture of Indium chloride and selenium dioxide in aqueous solution by electrodeposition technique on Indium Tin oxide coated glass substrates. The effects of the parameters during deposition such as current density, deposition potential versus saturated calomel electrode, pH value and concentration of source material were studied. X-ray diffraction studies were carried out on the films to analyze the microstructure using an x-ray diffractometer and were examined by RAMAN spectroscopy. The Raman peak position did not change much with chemical concentrations. Raman scattering due to the (LO) phonon was observed at 211 cm,1. Optical absorption studies were performed with a double beam ultra violet-visible ,NIR spectrophotometer in the wavelength 300,1100 nm. The surface morphology of the layer was examined using a scanning electron micrograph. The composition of the films was studied using an Energy Dispersive Analysis by X-Rays (EDAX). [source]


    Age Estimation by Pulp/Tooth Ratio in Canines by Peri-Apical X-Rays

    JOURNAL OF FORENSIC SCIENCES, Issue 1 2007
    Roberto Cameriere Ph.D.
    ABSTRACT: Estimation of age in individuals has received considerable attention in forensic science, in which it is a widely used method for individual identification, together with paleo-demographic analyses to establish mortality patterns in past populations. The present investigation, which is a continuation of a previously published pilot study, was conducted to examine the possible application of the pulp/tooth area ratio by peri-apical images as an indicator of age at death. A total of 200 peri-apical X-rays of upper and lower canines were assembled from 57 male and 43 female skeletons of Caucasian origin, aged between 20 and 79 years. They belong to the Frassetto osteological collection of Sassari (Sardinia) and are housed in the Museum of Anthropology, Department of Experimental and Evolutionistic Biology, University of Bologna. For each skeleton, dental maturity was evaluated by measuring the pulp/tooth area ratio on upper (x1) and lower (x2) canines. Very good agreement was found between intraobserver measurements. Statistical analysis was performed in order to obtain multiple regression formulae for dental age calculation, with chronological age as dependent variable, and gender, and upper and lower canines as independent variables. Stepwise regression analysis showed that gender did not contribute significantly to the fit (p=0.881) whereas variables x1 and x2 and the first-order interaction between them did. These two variables explained 92.5% of variations in estimated chronological age and the residual standard error was 4.06 years. Lastly, two simple linear regression equations were obtained for age estimation using canines from the maxilla and mandible separately. Both models explained 86% of variations in estimated chronological age and allowed an age-at-death estimate with a residual standard error of about 5.4 years. [source]


    Exposure of extremely low birth weight infants to diagnostic X-Rays: a longitudinal study

    ACTA PAEDIATRICA, Issue 2 2009
    Ilan Arad
    Abstract Aim: To quantify the number of chest and abdominal radiograms performed in surviving singleton extremely low birth weight (ELBW) infants in order to examine whether changes in imaging application occurred during the last 21 years (1987,2007). Methods: Clinical and radiological data of 225 out of 229 surviving infants were obtained and associations with time and clinical variables were evaluated. Results: The number of chest X-Rays performed per infant was 10.3 ± 11.1 (mean ± SD), median = 7; range = 0,77 and the number of abdominal radiograms was 5.6 ± 7.1, median = 3; range = 0,61. The number of chest and abdominal X-Rays performed per patient during 1987,1996 was very similar to that of 1997,2007, and no appreciable change of trend was observed along the years. There were negative and statistically significant correlations between the gestational age and the number of radiograms performed per patient (chest X-Rays: r =,0.402; p < 0.001, abdominal X-Rays: r =,0.182; p = 0.006). Controlling for gestational age, reduced numbers of radiograms per patient (abdominal: b =,1.20, p = 0.235; chest: b =,3.08, p = 0.035) were demonstrated in the second period. Patients with complicated clinical course were exposed to significantly more radiograms. Conclusion: Controlling for gestational age, a reduced number of exposures to chest radiograms was demonstrated during 1997,2007 compared with 1987,1996. Measures to reduce radiation, especially in complicated cases, are advocated. [source]


    Instant Volumetric Understanding with Order-Independent Volume Rendering

    COMPUTER GRAPHICS FORUM, Issue 3 2004
    Benjamin Mora
    Rapid, visual understanding of volumetric datasets is a crucial outcome of a good volume rendering application, but few current volume rendering systems deliver this result. Our goal is to reduce the volumetric surfing that is required to understand volumetric features by conveying more information in fewer images. In order to achieve this goal, and in contrast with most current methods which still use optical models and alpha blending, our approach reintroduces the order-independent contribution of every sample along the ray in order to have an equiprobable visualization of all the volume samples. Therefore, we demonstrate how order independent sampling can be suitable for fast volume understanding, show useful extensions to MIP and X-ray like renderings, and, finally, point out the special advantage of using stereo visualization in these models to circumvent the lack of depth cues. Categories and Subject Descriptors: I.3.3 [Computer Graphics]: Picture/Image, Generation, I.3.7 [Computer Graphics]: Three-Dimensional graphics and realism. [source]


    Three-Dimensional Surface Texture Characterization of Portland Cement Concrete Pavements

    COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 3 2007
    Ala Abbas
    Ten PCC field cores of varying surface textures were included in the analysis. X-ray Computed Tomography (CT) was used to scan the upper portion of these cores, resulting in a stack of two-dimensional grayscale images. Image processing techniques were utilized to isolate the void pixels from the solid pixels and reconstruct the three-dimensional surface topography. The resulting three-dimensional surfaces were reduced to two-dimensional "map of heights" images, whereby the grayscale intensity of each pixel within the image represented the vertical location of the surface at that point with respect to the lowest point on the surface. The "map of heights" images were analyzed using four mathematical methods, namely the Hessian model, the Fast Fourier transform (FFT), the wavelet analysis, and the power spectral density (PSD). Results obtained using these methods were compared to the mean profile depth (MPD) computed in accordance with ASTM E1845. [source]


    Metric spaces in NMR crystallography

    CONCEPTS IN MAGNETIC RESONANCE, Issue 4 2009
    David M. Grant
    Abstract The anisotropic character of the chemical shift can be measured by experiments that provide shift tensor values and comparing these experimental components, obtained from microcrystalline powders, with 3D nuclear shielding tensor components, calculated with quantum chemistry, yields structural models of the analyzed molecules. The use of a metric tensor for evaluating the mean squared deviations, d2, between two or more tensors provides a statistical way to verify the molecular structure governing the theoretical shielding components. The sensitivity of the method is comparable with diffraction methods for the heavier organic atoms (i.e., C, O, N, etc.) but considerably better for the positions of H atoms. Thus, the method is especially powerful for H-bond structure, the position of water molecules in biomolecular species, and other proton important structural features, etc. Unfortunately, the traditional Cartesian tensor components appear as reducible metric representations and lack the orthogonality of irreducible icosahedral and irreducible spherical tensors, both of which are also easy to normalize. Metrics give weighting factors that carry important statistical significance in a structure determination. Details of the mathematical analysis are presented and examples given to illustrate the reason nuclear magnetic resonance are rapidly assuming an important synergistic relationship with diffraction methods (X-ray, neutron scattering, and high energy synchrotron irradiation). © 2009 Wiley Periodicals, Inc.Concepts Magn Reson Part A 34A: 217,237, 2009. [source]


    High-precision measurement of internuclear distances using solid-state NMR

    CONCEPTS IN MAGNETIC RESONANCE, Issue 1 2008
    Jae-Seung Lee
    Abstract Today, nuclear magnetic resonance (NMR) is among the most efficient tools in structural studies. Measurement of interatomic distances is the most common way of determining high-resolution structures of molecules using NMR techniques. In this article, we describe NMR techniques for static powder samples, based on a two-dimensional single-echo scheme, enhanced with adiabatic cross-polarization. They can significantly increase the accuracy of measuring internuclear distances and turn NMR into a high-precision crystallographic technique, complementing the X-ray, and neutron-scattering methods. Experimental examples are presented for intramolecular CN and CC distances in ,-crystalline form of glycine. © 2008 Wiley Periodicals, Inc. Concepts Magn Reson Part A 32A: 56,67, 2008. [source]


    Micro-focus X-ray computed tomography images of the 3D structure of the cranium of a fetus with asymmetric double malformation

    CONGENITAL ANOMALIES, Issue 1 2006
    Takashi Shibata
    ABSTRACT,, Reconstructed micro computed tomography (Micro-CT, µ-CT) images have revealed the detailed three-dimensional structure of the cranium of human fetal congenital anomalies for the first time. The objects were a head and a cervix of female autosite and a parasite consisting of only a head conjoined to the scapular region of the autosite of an asymmetric double malformation (asymmetric conjoined twins, heteropagus twinning) at a gestational age of 8 months. The cranium of the autosite was normal, but that of the parasite was characterized by otocephaly (agnathia, synotia, and monorhina) and almost all the cranial bones were of an abnormal shape. It is suggested that a part of occipital bone (the basioccipital and exoccipital bones), the vomer and cribriform plate were absent and this resulted in the fusion and overlapping of bilateral temporal and craniofacial bones that should have been adjacent to them. This resulted in a reformation and relocation of most of the cranial bones. Micro-CT is a useful tool to visualize the detailed bone structure which has not been clarified by the conventional dissection methods and other imaging technologies and is a powerful instrument for studying congenital anomalies. [source]


    Radiological protection for diagnostic examination of pregnant women

    CONGENITAL ANOMALIES, Issue 1 2002
    Tomoko Kusama
    ABSTRACT, Application of diagnostic X-ray examination to pregnant women is complicated since risks to both mother and embryo/fetus must be considered. Embryos and fetuses are more sensitive to radiation than adults or children. The threshold doses for fetal death, malformations and mental retardation which are deterministic effects, are reported to be 100,200 mGy or higher. The relative risk for childhood cancer due to radiation at an absorbed dose of 10 mGy during embryonic/fetal development has been estimated at 1.4. However, the absorbed dose of the embryo/fetus during X-ray diagnostic examination in which the X-ray beam does not irradiate the embryo/fetus directly such as maternal skull and chest X-ray is extremely low, less than 0.01 mGy. Thus these diagnostic procedures are not a problem from the perspective of radiological protection of the embryo/fetus. However, for pelvic CT scan and barium enema in which the uterus is directly within the X-ray beam, the absorbed doses to the embryo/fetus are about 20,80 mGy and 10,20 mGy, respectively. Therefore, medical staff must pay careful attention to the embryo/fetus in application of these examinations. Pregnant women who were not aware of pregnancy at the time of their diagnostic exposure have great anxiety about radiation from such X-ray examinations. However, fetal doses below 100 mGy should not be considered a reason for terminating a pregnancy. [source]


    MR imaging in assessing cardiovascular interventions and myocardial injury

    CONTRAST MEDIA & MOLECULAR IMAGING, Issue 1 2007
    Alexis Jacquier
    Abstract Performing an MR-guided endovascular intervention requires (1) real-time tracking and guidance of catheters/guide wires to the target, (2) high-resolution images of the target and its surroundings in order to define the extent of the target, (3) performing a therapeutic procedure (delivery of stent or injection of gene or cells) and (4) evaluating the outcome of the therapeutic procedure. The combination of X-ray and MR imaging (XMR) in a single suite was designed for new interventional procedures. MR contrast media can be used to delineate myocardial infarcts and microvascular obstruction, thereby defining the target for local delivery of therapeutic agents under MR-guidance. Iron particles, or gadolinium- or dysprosium-chelates are mixed with the soluble injectates or stem cells in order to track intramyocardial delivery and distribution. Preliminary results show that genes encoded for vascular endothelial and fibroblast growth factor and cells are effective in promoting angiogenesis, arteriogenesis, perfusion and LV function. Angiogenic growth factors, genes and cells administered under MR-guided minimally invasive catheter-based procedures will open up new avenues in treating end-stage ischemic heart disease. The optimum dose of the therapeutic agents, delivery devices and real-time imaging techniques to guide the delivery are currently the subject of ongoing research. The aim of this review is to (1) provide an updated review of experiences using MR imaging to guide transcatheter therapy, (2) address the potential of cardiovascular magnetic resonance (MR) imaging and MR contrast media in assessing myocardial injury at a molecular level and labeling cells and (3) illustrate the applicability of the non-invasive MR imaging in the field of angiogenic therapies through recent clinical and experimental publications. Copyright © 2007 John Wiley & Sons, Ltd. [source]


    Tumor imaging in small animals with a combined micro-CT/micro-DSA system using iodinated conventional and blood pool contrast agents

    CONTRAST MEDIA & MOLECULAR IMAGING, Issue 4 2006
    Cristian T. Badea
    Abstract X-ray based micro-computed tomography (CT) and micro-digital subtraction angiography (DSA) are important non-invasive imaging modalities for following tumorogenesis in small animals. To exploit these imaging capabilities further, the two modalities were combined into a single system to provide both morphological and functional data from the same tumor in a single imaging session. The system is described and examples are given of imaging implanted fibrosarcoma tumors in rats using two types of contrast media: (a) a new generation of blood pool contrast agent containing iodine with a concentration of 130,mg/mL (FenestraŌ VC, Alerion Biomedical, San Diego, CA, USA) for micro-CT and (b) a conventional iodinated contrast agent (Isovue®-370,mg/mL iodine, trademark of Bracco Diagnostics, Princeton, NJ, USA) for micro-DSA. With the blood pool contrast agent, the 3D vascular architecture is revealed in exquisite detail at 100,µm resolution. Micro-DSA images, in perfect registration with the 3D micro-CT datasets, provide complementary functional information such as mean transit times and relative blood flow through the tumor. This imaging approach could be used to understand tumor angiogenesis better and be the basis for evaluating anti-angiogenic therapies. Copyright © 2006 John Wiley & Sons Ltd. [source]


    Epitaxial Sn1-xPbxS nanorods on iso-compositional thin films

    CRYSTAL RESEARCH AND TECHNOLOGY, Issue 6 2010
    K. Bente
    Abstract Based on SnS (Herzenbergite) , SnPbS2 (Teallite) mixed crystals with orthorhombic layer structures, thin films and lawns of Sn1-xPbxS nanorods were produced using hot wall vacuum deposition method (HWVD). The lawn was formed onto the surface of an underlying thin Sn1-xPbxS film which is build by differently oriented blocks. The density of rods arranged like a lawn depends on the metal ratio and substrate temperature. X-ray and TEM analysis of the epitaxial material showed preferential (001) orientation perpendicular to the surface of the glass substrate. The roughness of the films measured by atomic force microscopy was in the range of Rq = 49.5,86.3 nm depending on lead concentration The rods were about 500 nm high and 300 nm in diameter. As revealed by TEM-EDX experiments the droplet at the tip of rods consists of tin. Therefore it is assumed the rods grew via a self-consuming vapor,liquid,solid (VLS) mechanism. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Low temperature powder diffraction and DFT solid state computational study of hydrogen bonding in NH4VO3

    CRYSTAL RESEARCH AND TECHNOLOGY, Issue 9 2009
    . Smr
    Abstract The crystal structure of NH4VO3 was refined by the geometry optimization done by total energy minimization in solid state using DFT/plane waves approach. The lattice parameters were derived by the Le Bail technique from the low temperature X-ray (40-293 K) and synchrotron (100-293 K) powder diffraction data. The structure is formed by the infinite chains of irregular VO4 tetrahedra running approximately parallel to the c -axis, which are interlinked by the ammonium ions placed between them. The ammonium ions link to the [VO4], chains through one linear, one bifurcated and two trifurcated N-H,O hydrogen bonds. Considering their stability there are six distinct N-H,O hydrogen bonds: two strong with the N-H,O bond angles close to the straight, two medium with the bond angles of 123° and 148° and two very bent (105° and 107°) and hence weak hydrogen bonds. There is a reasonable agreement between the energies of the stretching ,(NH) modes estimated using the optimised N,O contact distances and those obtained experimentally. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Radiographic and Computed Tomographic Studies of Calcium Hydroxylapatite for Treatment of HIV,Associated Facial Lipoatrophy and Correction of Nasolabial Folds

    DERMATOLOGIC SURGERY, Issue 2008
    ALASTAIR CARRUTHERS MD
    OBJECTIVES This study sought to assess the radiographic appearance produced by calcium hydroxylapatite soft tissue filler (CaHA; Radiesse, BioForm Medical Inc.) following augmentation to correct the nasolabial folds or facial wasting associated with human immunodeficiency virus lipoatrophy. METHODS A total of 58 patients, with either lipoatrophy or pronounced nasolabial folds, were treated with CaHA. Radiographic (X-ray) and computed tomographic (CT) imaging studies were conducted pre- and posttreatment in most patients; the images were sent to an independent laboratory to be analyzed by two evaluators who were board-certified radiologists and blinded to study purpose, product, and patient condition. RESULTS While results for X-ray evaluation showed inconsistencies in visualization of CaHA, CT scans showed consistent visualization in nearly all cases in patients who were imaged immediately after treatment. In addition, the results indicated no obscuration of underlying structures by CaHA and no evidence of CaHA migration. CONCLUSIONS Earlier clinical trials established CaHA as a safe and effective soft tissue filler. This CaHA study shows no overt radiographic safety concerns. CaHA is unlikely to be confused with conventional abnormal and adverse radiographic findings. The product is not always visible on X-ray. Although usually visible on CT scans, its appearance is distinct from surrounding bony structures and does not interfere with normal analysis. In addition, the product does not obscure underlying structures on CT scans. [source]


    Polymicrobial lung infection in postrenal transplant recipient diagnosed by fine-needle aspiration cytology

    DIAGNOSTIC CYTOPATHOLOGY, Issue 4 2010
    Rajan Duggal M.D.
    Abstract Tuberculous and fungal infections are among the non-neoplastic lesions of the lung, in which fine-needle aspiration cytology (FNAC) has proven to be a useful technique in both immunocompromised and immunocompetent patients. The presence of polymicrobial infection in a renal transplant recipient is documented in the literature, but has rarely been diagnosed on cytology. We report a case of concomitant pulmonary cryptococcosis, aspergillosis, and tuberculosis in a renal transplant recipient diagnosed on FNAC. A 50-year-old renal transplant recipient, asymptomatic for 3 year, presented with intermittent low-grade fever associated with cough, expectoration, and a newly developed cavitatory lesion in the left lung on chest X-ray. Computed tomography-guided FNAC performed on the lung lesion showed fungal profiles with septate hyphae and acute-angled branching consistent with morphology of Aspergillus. In addition, numerous yeast forms of cryptococcus and a few acid-fast mycobacterial tubercle bacilli were seen. Guided FNAC is a useful and reliable technique for the diagnosis of pulmonary infection. One should always keep in mind the possibility of polymicrobial infections especially inimmunocompromised patients. Diagn. Cytopathol. 2010. © 2009 Wiley-Liss, Inc. [source]


    Intracytoplasmic lumina in invasive micropapillary carcinoma of the lung

    DIAGNOSTIC CYTOPATHOLOGY, Issue 3 2006
    Naoto Kuroda M.D.
    Abstract Micropapillary carcinoma of the lung is a rare neoplasm, and several reports on micropapillary carcinoma of the lung have been presented to date. We present a case of micropapillary carcinoma of the lung here. A 75-yr-old Japanese man received the medical checkup and his chest X-ray disclosed the abnormal shadow of the lower lobe of the left lung. The histological examination of resected lung and extirpated lymph node showed the finding of micropapillary carcinoma. Some neoplastic cells of primary site contained intracytoplasmic lumina positive for Alcian blue and PAS stains. Pleural effusion appeared 9-mo after the operation. The cytology of pleural effusion showed cohesive clusters of neoplastic cells consisting of 3,20 cells without fibrovascular core. Additionally, intracytoplasmic lumina were observed in some neoplastic cells. Finally, carcinoma cells with micropapillary morphology may possess the intracytoplasmic lumina in the cytoplasm of metastatic site as well as primary site. Diagn. Cytopathol. 2006;34:224,226. © 2006 Wiley-Liss, Inc. [source]


    WEGENER'S GRANULOMATOSIS COMPLICATED WITH APHTHOID COLITIS

    DIGESTIVE ENDOSCOPY, Issue 3 2006
    Yasushi Umehara
    A 58-year-old man was admitted with upper abdominal pain and high fever. There was no abnormality on chest X-ray, abdominal ultrasonography, abdominal CT and upper gastrointestinal endoscopy. Antineutrophil cytoplasmic antibodies (C-ANCA) titers were high and a chest CT scan depicted multiple nodules in the bilateral lungs. A diagnosis of Wegener's granulomatosis was therefore made. Three weeks after admission, diarrhea and bloody stool developed. Colonoscopy revealed many aphthoid lesions surrounded by redness in the entire colon. Although the biopsy from aphtha did not show vasculitis or granuloma, the aphthoid lesions were suspected as a complication of Wegener's granulomatosis. As a result of predonisolone medication (60 mg/day), the plasma C-reactive protein (CRP) and high fever improved promptly. In conclusion, although colonic involvement in a patient with Wegener's granulomatosis is extremely rare, it is important to keep in mind that colonic lesions might be due to vasculitis in ANCA-positive disease, such as Wegener's granulomatosis. [source]


    PEUTZ,JEGHERS POLYPOSIS WITH BLEEDING FROM POLYPS OF THE SIGMOID COLON SUCCESSFULLY TREATED BY LAPAROSCOPIC SURGERY

    DIGESTIVE ENDOSCOPY, Issue 1 2003
    Kazuhiro Yada
    We report a case of colonic bleeding complicating congestive heart failure in a patient with Peutz,Jeghers (P,J) polyposis successfully treated by laparoscopic surgery. A 49-year-old woman was admitted for severe cough and edema of the extremities. Chest X-ray revealed bilateral pleural effusion and cardiomegaly. Her cardiac function was within normal limits, but anemia and severe hypoproteinemia were observed. During the treatment, anal bleeding was observed. Endoscopic and radiographic examinations revealed hundreds of polyps from the duodenum to the rectum. 99mTc-diethylene triamine penta-acetic acid human serum albumin scintigraphy showed radiotracer collected in the sigmoid colon, the area having the most polyps. After some intestinal polypoid lesions were resected endoscopically, laparoscopy-assisted sigmoid colectomy and cecectomy were performed. In the postoperative course, she complained less about abdominal pain and her first flatus occurred on the third postoperative day. She recovered uneventfully. The anemia, hypoproteinemia, and congestive heart failure resolved and gastrointestinal bleeding has not been seen. It was thought that protein loss and hemorrhage due to the P,J polyposis caused congestive heart failure. When congestive heart failure is accompanied by gastrointestinal hemorrhage, it is important to consider hypoproteinemia due to gastrointestinal polyposis, such as that characterizing P,J syndrome. Laparoscopic surgery was very useful for the treatment of colonic bleeding. [source]


    Preparation and Characterization of a Tin Pentacyanonitrosylferrate-Modified Carbon Ceramic Electrode: Application to Electrocatalytic Oxidation and Amperometric Detection of L -Cysteine

    ELECTROANALYSIS, Issue 7 2009
    H. Razmi
    Abstract The sol-gel technique was used to construct tin pentacyanonitrosylferrate (SnPCNF) modified composite carbon ceramic electrode (CCE). This involves two steps: construction of CCE containing metallic Sn powder and then electrochemical creating of SnPCNF on the surface of CCE. The SnPCNF modified CCE (SnPCNFlCCE) was characterized by energy-dispersive X-ray (EDX), FTIR and cyclic voltammetry (CV) techniques. The SnPCNF film showed electrocatalytic activity toward the oxidation of L -cysteine. A linear calibration plot was obtained over the L -cysteine concentration range 1,51,,M using chronoamperometry. L -cysteine was determined amperometrically at the surface of this modified electrode. The detection limit (for a signal to noise of 3) and sensitivity were found to be 0.62,,M and 126,,A/mM, respectively. [source]


    Preparation, Electrochemistry, and Electrocatalytic Activity of Lead Pentacyanonitrosylferrate Film Immobilized on Carbon Ceramic Electrode

    ELECTROANALYSIS, Issue 21 2008
    H. Razmi
    Abstract Lead pentacyanonitrosylferrate (PbPCNF), a new Prussian blue analog, was immobilized on the surface of a carbon ceramic electrode (CCE) prepared by sol-gel method. The immobilization process consists of adding a certain amount of metallic lead to the electrode matrix before gelation, and chemical derivatization of Pb on the electrode surface to a PbPCNF solid film by immersing the electrode in a solution of sodium pentacyanonitrosylferrate (PCNF). The composition of the synthesized PbPCNF was characterized by FTIR, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) techniques. The resulting modified electrode showed electroactivity at two redox centers. The electrochemical behavior of the PbPCNF modified carbon ceramic electrode (PbPCNF|CCE) was studied by cyclic voltammetry. Under optimized conditions the peak-to-peak separation is only 39,mV, indicative of a surface reaction. Ion effects of the supporting electrolyte suggest that cations have a considerable effect on the electrochemical behavior of the modified electrode. The transfer coefficient (,) and the charge transfer rate constant at the modifying film|electrode interface (ks) were calculated. The electrocatalytic activity of the modified electrode toward the electro-reduction of peroxodisulfate was studied in details. [source]